The present invention relates to means for controlling environments in medical treatment applications, and more particularly to an enclosure for maintaining high relative humidity and sufficient oxygen in the region about a patient's head and upper body.
Nebulized vapor or mist is widely recognized as an effective therapy to alleviate the symptoms of croupe, asthma and upper respiratory diseases in general. Devices for providing moist air therapy are available for hospital and household settings. In hospitals, the typical approach is to employ an oxygen tent constructed of flexible, pliable and transparent plastic sheeting or film, draped over a bed to form an enclosure surrounding at least the upper body of the patient. Oxygen is supplied to the tent interior, usually at a controlled, steady rate. The oxygen or air supplied to the tent can be humidified to the extent desired. These systems are expensive, however, and require physicians, nurses or other skilled personnel to monitor conditions within the oxygen tent to insure the safety and comfort of the patient.
Moist air treatment devices have been developed for household use. Such devices are substantially less expensive and require less skill to operate and monitor as compared to a hospital oxygen tent, although they do not afford the same degree of environmental control. Examples of these devices include cool mist vaporizers, warm mist vaporizers (sometimes referred to as "steamers") and ultrasonic vaporizers. Typically such vaporizers generate a stream of moist air in the form of multiple suspended droplets in the range of about three to five micrometers in diameter. The effectiveness of these devices depend substantially on the degree to which the moist air stream can be directed toward the nose and mouth of the patient. Further, the devices tend to increase the relative humidity of the entire room in which the patient is situated. Humidity sufficiently high to treat the patient can be a source of discomfort to others, and has undesired consequences, e.g. promoting the growth of molds that thrive in humid environments.
One approach to containing a treatment environment in a household setting is shown in U.S. Pat. No. 3,878,570 (Donnelly). The Donnelly patent discloses a crib attachment including a detachable frame and a flexible canopy supported by the frame over the crib to enclose the crib in a semi-airtight manner. The canopy is preferably transparent. An environmental control apparatus mounted to the crib includes a blower for drawing room air, an air filter, a heater, and a damp sponge for humidifying the air. A flexible hose supplies the filtered, heated and humidified air to the tent interior.
U.S. Pat. No. 3,905,056 (Rosendahl) discloses a mist-oxygen therapy crib liner tent including a bottom situated under a crib mattress, and four side panels extending upwardly from the bottom panel along the sides of the crib. The tent can be placed, inverted, over a conventional therapy tent frame, and a opening cut out of the bottom (top in the inverted position) to provide a mist-oxygen enclosure. In U.S. Pat. No. 4,641,387 (Bondy et al), plastic sheet material and cooperating netting are employed to form transparent panels about the top, opposed sides and opposed ends of a bed, to provide what is said to be a bed enclosure which is not mentally or physically intimidating to the patient.
While each of the above devices is perhaps useful in certain situations, there remains a need for a low cost, safe and effective means for providing a confined, high humidity treatment enclosure for household use.
Therefore, it is an object of the present invention to provide a means for developing and sustaining a high humidity environment about an individual for respiratory therapy, without the need for an oxygen supply, pump, blower or other special equipment.
Another object of the invention is to provide an enclosure that effectively confines a high humidity environment to the region about an individual under treatment, while insuring an adequate oxygen supply and preventing accumulation of carbon dioxide.
Yet another object is to provide a system employing a conventional household vaporizer to maintain a controlled, high humidity treatment environment in the region of an individual's head and upper body.